Cavity back for a golf club head



FIG. 1 is an elevational view of the back of the club head showing my new design;

FIG. 2 is a perspective view thereof; and,

FIG. 3 is another perspective view thereof.

The broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a cavity back for a golf club head, as shown and described. 